The American Cancer Society estimates that this year alone 564,800 Americans will die of cancer. Scientific evidence also suggests that up to one-third of those deaths are related to malnutrition and cachexia. There are currently no effective nutritional interventions designed to treat the complex syndrome of cancer cachexia. The presence or absence of weight loss is a predictor of survival in patients receiving cancer therapy. Supplemental nutrition is often indicated in severely malnourished patients undergoing surgery, chemotherapy, or radiation therapy. Our goal is to prevent treatment-related morbidity and mortality, deliver optimal anti-neoplastic therapy, alleviate symptoms of cancer cachexia, and improve quality of life. Forty patients with solid tumors who have demonstrated weight loss of 5% or greater in the previous six weeks will be recruited for the study. Patients will be supplemented with either the nutrient combination HMB/arginine/glutamine or a placebo in a double blind fashion. For a period of 24 weeks, body composition will be evaluated by air displacement, plethysmography, bioelectrical impedance analysis, skinfold testing, and circumference measurements. We expect that the HMB/arginine/glutamine combination will result in a positive synergistic action on muscle mass which is anticipated to help cancer patients better tolerate chemotherapeutic regimens and improve longevity and quality of life. PROPOSED COMMERCIAL APPLICATIONS: If this nutritional combination can enhance immune function and lean mass in cancer patients, it will be possible to market this combination in a variety of products. Since over 1.2 million cases of cancer are expected to be diagnosed this year alone (American Cancer Society), there is a large market potential for the proposed nutritional product. The initial product would most likely contain the nutrient combination in a ready-to-drink formulation. A balanced nutritional product containing high quality protein and other nutrients would likely follow. It is envisioned that these products will be highly effective over-the-counter nutritional supplements for cancer patients with diagnosed symptoms of cachexia and result in better treatment outcomes and improved quality of life for the patients.